Photophysical and Nonlinear Optical Properties of Azophloxine in Reverse Micelles.

The photophysical and nonlinear optical properties of Azophloxine in Reverse micelle (RM) and dye-surfactant interaction were studied using Z-scan, spectrophotometer, and spectrofluorometer techniques. The different range of RM sizes and oil polarity is studied. RM is a mixture of water droplet in a continuous phase of oil and its polarity depends on oil polarity. The nonlinear absorption coefficient (β) and nonlinear refractive index (n) of Azophloxine in RM depend on the polarity of bulk. By using the NMR instrument, it was observed that the Azophloxine dye is intercalated in the reverse micelles in AOT/Water/Benzene solution and its average location corresponds with the core of the micelle close to polar groups of the surfactant. The rule of charge and length scale of surfactant on the value of β and n of Azophloxine is studied. The results showed that the enhancement value of β and n is due to the solubility reduction of Azophloxine with the anionic surfactant in aqueous solutions or increase of oil length scale in RM. The quantum perturbation theory was used to study the ratio of excited to ground state dipole moment of Azophloxine in RM. By using dynamic light scattering, it was observed that the size of RM reduced with an increase of dye concentration in RM.